Genomic characterization of extended-spectrum ß-lactamase-producing Enterobacterales isolated from abdominal surgical patients.

Rectal swabs of 104 patients who underwent abdominal surgery were screened for ESBL producers. Sequence types (STs) and resistance genes were identified by whole-genome sequencing of 46 isolates from 17 patients. All but seven isolates were assigned to recognized STs. While 18 ESBL-producing E. coli (EPEC) strains were of unique STs, ESBL-producing K. pneumoniae (EPKP) strains were mainly ST14 or ST15. Eight patients harboured strains of the same ST before and after abdominal surgery. The most prevalent resistant genes in E. coli were blaEC (69.57%), blaCTX-M (65.22%), and blaTEM (36.95%), while blaSHV was present in only K. pneumoniae (41.30%). Overall, genes encoding ß-lactamases of classes A (blaCTX-M, blaTEM, blaZ), C (blaSHV, blaMIR, and blaDHA), and D (blaOXA) were identified, the most prevalent variants being blaCTX-M-15, blaTEM-1B, blaSHV-28, and blaOXA-1. Interestingly, blaCMY-2, the most common pAmpC ß-lactamase genes reported worldwide, and mobile colistin resistance genes, mcr-10-1, were also identified. The presence of blaCMY-2 and mcr-10-1 is concerning as they may constitute a potentially high risk of pan-resistant post-surgical infections. It is imperative that healthcare professionals monitor intra-abdominal surgical site infections rigorously to prevent transmission of faecal ESBL carriage in high-risk patients.

A randomized controlled study comparing the efficacy of soap versus soap-plus-microwave disinfection for irrigation device in children with acute rhinosinusitis.

BACKGROUND: Nasal irrigation is an effective component of sino-nasal disease management. Nonetheless, bacterial contamination is worrisome. OBJECTIVE: To study bacterial colonization incidence using squeeze-bottle nasal irrigation devices, after disinfection with soap or soap-plus-microwave technique, in pediatric acute rhinosinusitis. METHODS: A randomized, prospective, controlled study was conducted on acute rhinosinusitis children, aged 2-15 years. Each participant was randomized into a soap-cleaning or soap-plus- microwave group. For a two-week period, participants irrigated their nostrils with NSS twice daily and cleaned the bottle after each use. In the end, bottles were sent to a microbiological laboratory for bacterial identification. RESULTS: The mean 5S Score and satisfaction score gradually improved in both groups with no significant differences between groups. Bacterial identification frequency in the soap group was slightly higher than in the soap-plus-microwave one, without statistical significance. For safety and tolerability, all participants reported 100% adherence to nasal irrigation. The soap-plus-microwave group reported more minor adverse outcomes than the soap-cleaning one. No thermal deformation of irrigation bottles was observed. CONCLUSIONS: Regular cleaning of nasal irrigation devices is needed to minimize bacterial contamination. Only soap or soap plus microwave disinfection appeared simple and safe for disinfection. Both techniques can equally minimize the rate of bacterial contamination. Although no gross thermal deformation at optimal power and duration, chemical irritants after high power or long microwave durations may be a concern.

Molecular characterization of methicillin-resistant Staphylococcus aureus genotype ST764-SCCmec type II in Thailand.

Methicillin-resistant Staphylococcus aureus (MRSA) is a significant causative agent of hospital-acquired infections. We characterized MRSA isolated from August 2012 to July 2015 from Thammasat University Hospital. Genotypic characterization of MRSA SCCmec type II and III isolates were scrutinized by whole genome sequencing (WGS). The WGS data revealed that the MRSA SCCmec type II isolates belonged to ST764 previously reported mainly in Japan. All of tested isolates contained ACME Type II', SaPIn2, SaPIn3, seb, interrupted SA1320, and had a virulence gene profile similar to Japan MRSA ST764. Rigorous surveillance of MRSA strains is imperative in Thailand to arrest its potential spread.

Outcomes of extended-spectrum beta-lactamases producing Enterobacteriaceae colonization among patients abdominal surgery patients.

Preoperative enteric screening for extended-spectrum ß-lactamase (ESBL)-producing Enterobacteriaceae was conducted in 360 patients prospectively observed for surgical site infection (SSI). ESBL colonization (adjusted odds ratio [aOR], 2.4) and dirty wound classification (aOR, 3.6) were associated with SSI; no association between carbapenem prophylaxis and reduction in SSI was detected.

PREVALENCE AND ANTIBIOTIC SUSCEPTIBLITY OF METHICILLIN RESISTANT STAPHYLOCOCCUS AUREUS, COLLECTED AT THAMMASAT UNIVERSITY HOSPITAL, THAILAND, AUGUST 2012 - JULY 2015.

We analyzed data of Staphylococcus aureus isolated from patients attending Thammasat University Hospital, Thailand from August 2012 to July 2015. In total, 232/502 (46%) S. aureus isolates were methicillin-resistant S. aureus (MRSA). There was a declining trend of proportion of MRSA infection, but the prevalence of MRSA in the last year of study remained high (38%). All 32 MRSA-infected outpatients had history of exposure to healthcare facilities during the previous two months and thus were not considered as having community-associated MRSA. In addition, all these strains were negative for pvl, suggesting that these strains were hospital-associated MRSA. All MRSA stains were susceptible to linezolid, teicoplanin and vancomycin, but resistance to erythromycin and clindamycin were nearly 100%. Fifty-two percent and 87% of MRSA strains were susceptible to tetracycline and trimethoprim-sulfamethoxazole, respectively. These results emphasize the necessity of long-term surveillance and monitoring of antimicrobial susceptibility pattern of MRSA.

Decontamination Efficacy of Ultraviolet Radiation against Biofilms of Common Nosocomial Bacteria.

BACKGROUND: Ultraviolet radiation (UV) is commonly used to destroy microorganisms in the health-care environment. However, the efficacy of UV radiation against bacteria growing within biofilms has never been studied. OBJECTIVE: To measure the sterilization effectiveness of UV radiation against common healthcare associated pathogens growing within biofilms. MATERIAL AND METHOD: Staphylococcus aureus, Methicillin-resistant S. aureus (MRSA), Streptococcus epidermidis, Escherichia coli, ESBL-producing E. coli, Pseudomonas aeruginosa and Acinetobacter baumannii were cultivated in the Calgary Biofilm Device. Their biofilms were placed 50 cm from the UV lamp within the Biosafety Cabinet. Viability test, crystal violet assay and a scanning electron microscope were used to evaluate the germicidal efficacy. RESULTS: Within 5 minutes, UV radiation could kill S. aureus, MRSA, S. epidermidis, A. baumannii and ESBL-producing E. coli completely while it required 20 minutes and 30 minutes respectively to kill E. coli and P. aeruginosa. However, the amounts of biomass and the ultrastructure between UV-exposed biofilms and controls were not significantly different. CONCLUSION: UV radiation is effective in inactivating nosocomial pathogens grown within biofilms, but not removing biofilms and EPS. The biofilm of P. aeruginosa was the most durable.

Antimicrobial activity of Gynostemma pentaphyllum extracts against fungi producing aflatoxin and fumonisin and bacteria causing diarrheal disease.

Gynostemma pentaphyllum was investigated to determine its antimicrobial activities against human.and animal pathogens that produce aflatoxin, fumonisin, and diarrheal disease. The fungi were Aspergillusflavus, Aspergillus parasiticus and Fusarium verticillioides. The bacteria were Vibrio, Salmonella, Shigella, Escherichia coli and Staphylococcus aureus. G. pentaphyllum was extracted by five different methods. The obtained extracts were designated Extracts A, B, C, D and E. The results of the antifungal assay against A.flavus andA. parasiticus showed Extracts A and B at 10,000 ppm inhibited growth at 8-28%. Extracts A and B at 10,000 ppm also showed activity against F. verticillioides at 41-43%. Extract A, B and C were able to inhibit the tested strains better than the Extracts D and E. The MIC values of the extracts against gram-negative bacteria ranged from

Antimicrobial activity of rice bran extracts for diarrheal disease.

BACKGROUND: Rice bran showed antioxidative, antimutagenic, carcinogenic and antibacterial activities in previous reports. The rice bran has been recently used as a natural source of health food for several diseases such as diabetes, atherosclerosis and cancer. Severe diarrheal disease due to food-borne contamination of bacteria resulted from the bacteria have become resistant to many antibiotics. Hence, early treatment of diarrhea using natural food containing antibacterial activity to prevent progression of severe symptoms will be beneficial. OBJECTIVE: To investigate antimicrobial activity of rice bran extracts against bacteria causing diarrheal disease. MATERIAL AND METHOD: Bacterial strains isolated from patients include Vibrio cholerae, Vibrio vulnificus, Salmonella spp, Shigella spp, Escherichia coli (ETEC, EHEC, EAEC, EPEC, EIEC) and Stahylococcus aureus. Rice bran was extracted by five different extraction techniques. The antimicrobial activity was performed by disk diffusion and broth dilution methods. RESULTS: The results showed that rice bran extracts using different techniques of extraction were able to inhibit the growth of test strains. Rice bran extracts exhibited the most effective antibacterial activity against V. cholerae O139 with MIC value of 0.976 mg/ml. Using ethanol and supercritical techniques, Sang-Yod rice bran showed better antibacterial activity than Jasmine rice bran. In the present study, the MIC values of rice bran extracts against all tested strains except V. cholerae O139 and S. aureus were between 7.812 to 31.25 mg/ml. CONCLUSION: The results of present study provide insighful basic knowledge which would lead to develop rice bran extracts for effective treatment of diarrheal disease causing by bacteria including resistant strains. The rice bran extracts used against bacterial infection will be an alternative remedy in order to reduce the incidence of antibiotic resistance in future.

Antibacterial activity of crude extracts of prasaprohyai formula and its components against pathogenic bacteria.

BACKGROUND: Prasaprohyai formula is a Thai Traditional Medicine which has been used for reducing feverish in child. Fever is a symptom resulting from various infections and diseases. The major cause of fever is bacterial and viral infections. The Prasaprohyai formula and its components potentially have biological activities including antipyretic and antimicrobial activities. It is in a hope to develop the formula and its components for an alternative medicine of infectious diseases. OBJECTIVE: To study antibacterial activity of Prasaprohyai formula and its components against pathogenic bacteria. MATERIAL AND METHOD: Prasaprohyai formula and its components were extracted by different methods, A: maceration with 95% ethanol followed by evaporation (ET), B: ET followed by freeze drying (EF) and C: water distillation (VO). All extracts were tested against clinical isolates from Thammasat University Hospital, Staphylococcus aureus ATCC 25923 and Escherichia coli ATCC 25922. Disk diffusion and broth dilution methods were performed. RESULTS: Crude extracts of ET had higher yield of extraction than other methods. The results showed that the crude extract from different methods of Syzygium aromaticum (Linn) Merr & Perry (Flower) was effective against all bacterial strains with the inhibition zone ranging from 9 to 19 mm. The VO extract of Prasaprohyai formula showed antibacterial activity against most of the pathogenic bacteria in the present study. The activity against Streptococcus pyogenes was found in the VO extract of some components. The ET extracts of Lepidium sativum Linn, Myristica fragrans Houtt (seed) and Myristica fragrans Houtt (aril) had no antibacterial activity against all microorganism. However the EF extracts of this formula and some components were able to mostly inhibit Gram positive bacteria. CONCLUSION: The results indicated that Prasaprohyai formula and its components were able to inhibit the growth of both Gram positive and Gram negative bacteria including multiresistant strains. The volatile oil extracts seemed to play an important role in antimicrobial activities. The development of Prasaprohyai formula for alternative medicine will be approached in future.

Bacterial contamination assay of Thai herbal products.

BACKGROUND: Herbal products have been globally used for health promotion. These products were frequently contaminated with various microorganisms due to raw materials and unhygienic production process. Microbiological quality of several forms is necessary to determine by microbial contamination assay in order to assure the safety of Thai herbal products. OBJECTIVE: To investigate the microbiological quality of Thai herbal products commercially distributed from different regions of Thailand and marketed in Bangkok and Pathumthani province by bacterial contamination assay. MATERIAL AND METHOD: Thai herbal products were randomly collected in Bangkok and Pathum Thani province. Total of 94 samples were in different dosage forms including liquids, pills, capsules and powders. The samples were divided into two groups as Standard Certified and Non-Certified herbal products. The products were tested as plate count method using spread plate technique. The obtained results were interpreted based on Thai Herbal Pharmacopoeia. RESULTS: The total plate counts of Standard Certified samples were ranged between less than 30 to 5.8 x 10(7) cfu/g or ml and the Non-Certified samples were ranged between less than 30 and 6.0 x 10(6) cfu/g or ml. In addition, the results showed that 7 out of 49 (14.28%) of Standard Certified sample group and 5 out of 45 (11.11%) of the Non-Certified sample group were out of the range of acceptable standard. The finding indicated that the microbiological quality of both Standard Certified and Non-Certified Thai herbal products showed no significant differences. CONCLUSION: Majority of the herbal products tested for bacterial contamination were in acceptable standard. However some products were out of acceptable range. Hence the rigorous assessment of quality control and good manufactury practice of Thai herbal production is necessary for safe consumption.

Antimicrobial activity of the extracts from Benchalokawichian remedy and its components.

BACKGROUND: Infectious diseases cause serious health problems worldwide due to multiresistant bacterial strains. Thai traditional formula such as Benchalokawichian remedy has been used to relieve fever, common cold and influenza. The remedy has been scientifically proved for antipyretic and antiseptic activities. However; the remedy and its components have not been fully studied for antimicrobial activity against pathogenic bacteria. OBJECTIVE: To determine antimicrobial activity of extracts from Benchalokawichian remedy and its components against clinical isolates by disk diffusion method. MATERIAL AND METHOD: The bacterial strains used in the present study were clinical isolates from Thammasat Hospital, Thailand. The ethanolic and water extracts of Benchalokawichian remedy and its components were screened for antimicrobial activity. The tests were performed in triplicate. The results were recorded by measuring diameter of growth inhibition zone. Means +/- SD of the obtained results were calculated. RESULTS: The results of antimicrobial activity demonstrated that the ethanolic extracts of Benchalokawichian remedy and its components were effective against Candida albicans, Gram positive and Gram negative bacteria except some isolates. Tiliacora triandra and Clerodendrum petasites exhibited the most effective antimicrobial activity among other ethanolic extracts. The water extracts of Capparis micracantha, Tiliacora triandra and Harrisonia perforata were able to inhibit the tested strains. Both etahnolic and water extracts of Tiliacora triandra were the only one component of Benchalokawichian remedy that could inhibit the growth of C. albicans. CONCLUSION: The present study provides basic knowledge of the antimicrobial activity of Benchalokawichian remedy and its components. Tiliacora triandra and Clerodendrum petasites were the most effective antimicrobial activity among other ethanolic extracts. They are potential candidates to produce medicinal formula for alternative medicine. Further study on minimum inhibitory concentration and minimum bactericidal concentration assay will be carried out in order to obtain more detailed insightful knowledge to develop medicinal products for treatment of bacterial infection and other infectious diseases.

Antibacterial activity of extracts from five medicinal plants and their formula against bacteria that cause chronic wound infection.

BACKGROUND: Chronic wound is caused by various factors such as chemotherapy, gene damage, treatment with steroids, diabetes mellitus, renal failure, blood pressure, infection and nutritional factors. One of the most common causes is bacterial infection. Antibacterial activity of several herbal plants has been reported. Thai medicinal plants which possess biological activities are potential to develop an alternative treatment of bacterial infection. OBJECTIVE: To study efficiency of extracts from medicinal plants and their formula against bacteria that cause chronic wound infection. MATERIAL AND METHOD: Extraction of Thai medicinal plants including Curcuma longa Linn, Rhinacanthus nasutus Linn, Garcinia mangostana Linn, Caesalpinia sappan Linn and Centellia asiatica Linn was performed by maceration with 95% ethanol and decoction followed by freeze dry. Formulation was conducted by varying the ratio of each components. Antibacterial activity were determined disk diffusion and broth dilution against Staphylococcus aureus, Methicillin-resistant Staphylococcus aureus (MRSA), Pseudomonas aeruginosa, Acinetobacter baumanii, Escherichia coli and Klebsiella pneumoniae. RESULTS: Ethanolic extracts exhibited better antibacterial activity against tested strains than water extracts. Antibacterial activity of Caesalpinia sappan Linn. against S. aureus and MRSA showed the most effective with MIC value of 0.625 mg/ml. One of the five different formulas which contained two times proportion of C. sappan revealed that this formula was able to inhibit all tested strains with the MIC ranging between 0.156 mg/ml and 10 mg/ml. CONCLUSION: C. sappan is the most effective herbal plant. The formula with two times proportion of C. sappan is potentially best formula for development of medicinal product of chronic wound infection. The potential active compound of C. sappan is suggested for further investigation of antimicrobial activity and other biological properties.

Pulsed field gel electrophoresis analysis of Vibrio cholerae isolates in southern Thailand.

Forty isolates of V. cholorae O1, O139 and non-O1/non-O139 collected from outbreaks in Songkhla and Phuket Provinces of southern Thailand during 1999-2001 and sporadic cases from different regions of Thailand during 1993-2002 were characterized using pulsed field gel electrophoresis (PFGE). Digestion of chromosomal DNA of the V cholerae isolates with restriction endonuclease NotI, followed by PFGE, generated 10 distinct restriction endonuclease analysis patterns consisting of 8 to 13 bands, ranging in size from 78 to 394 kb. PFGE patterns of O1 Inaba strains from the outbreak in Songkhla were identical (P1) except one isolate (P3). The O1 Inaba outbreak strains from Phuket in the same period belonged to P2 pattern, whereas the O1 Ogawa strain from the outbreak in Phuket isolated in 1999 was of P7 pattern. These patterns of O1 Inaba and Ogawa strains were slightly different suggesting that the isolates were epidemiologically related and therefore the outbreaks were likely due to the same V cholerae clone. Isolates of V cholerae O1 Inaba from sporadic cases in the neighboring area (e.g., Pattani Province) in a similar period of time of the outbreak in Songkhla Province had very similar patterns, with only one single band different from those of the outbreak isolates. This indicates that the Inaba strains isolated from Songkhla Province during the 2001 cholera outbreak belonging to P1 pattern had not spread to other regions in 2001 and 2002. On the otherhand, the sporadic isolates collected from other regions of Thailand were quite distinct from the outbreak isolates in Songkhla Province, especially those from Chaiyaphum and Chaing Mai Provinces, which belonged to P5 and P6 pattern, respectively. Isolates of V cholerae O139 and non-O1/non-O139 gave different patterns from that of V. cholerae O1. This study shows that the PFGE technique is markedly advantageous in distinguishing strains of V cholerae isolates leading to insightful detailed charateristics of these isolates in Thailand.

Antibacterial activity of Thai medicinal plants Pikutbenjakul.

BACKGROUND: Bacterial infections caused by resistant strains have been increased dramatically. Pikutbenjakul, a Thai medicinal plant formula containing Piper longum, Piper sarmentosum, Piper interruptum, Plumbago indica and Zingiber officinale have been widely used in Thai traditional medicine. OBJECTIVE: To determine antimicrobial activity of Pikutbenjakul formula and its components in order to develop the medicinal plants for alternative treatment of bacteria causing diarrhea. MATERIAL AND METHOD: Activity of Pikutbenjakul formula and its components was tested using disc diffusion and broth dilution methods against bacteria associated a set of bacteria associated with diarrheal disease including Vibrio cholerae, Vibrio vulnificus, Salmonella, Shigella, Escherichia coli (EIEC, ETEC, EPEC, EAEC and EHEC) and Staphylococcus aureus. The extraction was performed by maceration in 95% ethanol. RESULTS: The results showed all tested strains were susceptible to P. indica while other components were able to inhibit some strains. P. sarmentosum showed antimicrobial activity against Vibrios with the MIC values between 0.625 to > or =5 mg/ml. P. sarmentosum, P. indica and Pikutbenjakul formulas inhibited the growth of all Vibrios. P. interruptum inhibited V. cholerae serogroups O1 and non-O1/non-O139. P. longum was able to inhibit only two isolates of V. cholerae serogroup O139 (MIC = 1.25 mg/ml) and V. vulnificus (MIC > or =5 mg/ml). The activity of Pikutbenjakul containing Zingiber spp. and Pikutbenjakul containing Z. officinal against Vibrios, Shigella spp. and S. aureus was not significantly different. P. indica could inhibit Salmonella (MIC > or =5 mg/ml), E. coli (MIC > or =5 mg/ml) and S. aureus (MIC = 1.25 mg/ml). CONCLUSION: The results support the Thai medicinal plants for treatment of diarrhea caused by these bacteria. This study also provides an insightful knowledge on antimicrobial activity which would lead to further development of an effective formula of Pikutbenjakul for diarrheal disease and other infectious diseases in future.

Distribution and sequence analysis of virulence associated genes in Vibrio cholerae O1, O139 and non-O1/non-O139 isolates from Thailand.

Virulence-associated genes of Vibrio cholerae including O1, O139 and non-O1/non-O139 from an outbreak in Songkhla Province and sporadic cases occurred in Thailand during 1993 - 2002 were investigated. One hundred eighty-five V. cholerae strains were examined for the presence of virulence-associated genes including ctxA, tcpA, zot, toxR, toxS, toxT, and ace by polymerase chain reaction. DNA sequences of ctxA, tcpA, zot and toxR also were investigated in 8 selected isolates. Results showed that the virulence factors genes were distributed in the majority of V cholerae O1 biotype Inaba and Ogawa strains (85-97%). All 6 strains of the O139 harbored toxR, toxS and toxT whereas ctxA, tcpA, zot and ace were detected only 50-67%. Toxins genes found in non-O1/non-O139 strains ranged 8-30% except toxR (73.5%). Results of multiple sequence alignments among the isolates compared with V. cholerae O1 in database (embl M21249), showed that ctxA, tcpA and zot sequences in all 8 isolates were conserved, but base changes were found in toxR sequence. These molecular characteristics of V cholerae isolated from Thailand will provide detailed information for facilitating future studies on the development and design of appropriate vaccine providing protection against local strains.